Method of refining glyceride-type oils



Feb. 13, 1940. B, CLAYTON 2,190,588

METHOD OF REFINING GLYCERIDETYPE OILS Filed Jan. 4, 1957 A rroR/vfy.

Patented Feb. '13, 1940 UNITED STATES 2,190,588 METHOD 0F REFINI GLYCERIDE-TYPE Benjamin Clayton, Sugarland, Tex.,` assigner to Refining, Inc., Reno, Nev., a corporation o! 1 Nevada Application January yt., 1937, serial No. 119,022

zo claims.

My invention relates to a novel method and apparatus for refining glyceride-ty'pe oils, and has among its objects the lowering of refining losses without increasing the color of the refined oil, in many instances producing an oil of better color, as evident either by the refined oil when rst separated or after conventional washing, drying and bleaching thereof.

A crude. glyceride-type oil contains free fatty acids and other impurities. For example, crude cottonseed oil may contain free fatty acids ranging in quantity from a fraction of one percent to more than two percent. It is common practice to refine such glyceride-type oils. by use of an alkali refining agent, usually in dilute aqueous solution, such as caustic sodal or caustic potash. These and other refining agents ca' p able of reacting or combining with the impurit1es to form foots and thus rening the 'oil are herein included in the term refining reagent.

While such refining reagents have a prefer ential ainity for the free fatty acids, they also tend to react with the oil itself. The loss in volume of a crude glyceride-type oil during such refining is called the refining loss. It is made up partly of the loss due to the formation of foots fromy the 4free fatty acids kand other impurities initially in the oil, a necessary loss, and partly of the loss due to the action of the reagent on 'the oil itself and the entrainment of neutral oil with the separated foots, a loss whichV is very materially decreased in the present to add a greater quantity of the refining reagent than is theoretically necessary vto neutralize the free fatty acids, the excess acting `to produce a proper bleach by removing objectionable color. However, in conventional batch treatment 'this excess tends to saponify a portion of the neu-- tral oil, thus increasing the refining loss.

In reacting or combining with the' impurities, the refining reagent forms foo'ts or soapstock. These foots are composed primarily ofsoap and various color impurities and are in the form of minute particles which tend to settle if allowed to stand quiescent. `Oil may be associated there-` with either by being` emulsified within the particles, or by being entrained inthe voids between such particles. Usually both types of association may coexist, especially if gravitational separation is utilized.. In a continuous refining system utilizing a centrifuge for separating the oil and the foots it is possible to 'recover most of the oil in these voids, but the present invention goes even further in seeking to eliminate in addition losses due to the emulsifled oil.

AI have found it possible to decrease very materially saponification'of neutral oil and reduce the amount of oil in the soapstock without increasing the color of the refined oil, even often producing an oil of better color, by proper use of a third material. This material is an agent whichl acts, in the quantities used, as a delo emulsifying agent and as an inhibitor for saponiflcation of neutral oil, being hereinafter termed a de-emulsifying and inhibiting agent. It is preferably volatile and has a tendency to break or prevent the formation of the usual uniformly emulsied character of the soapstock. Its power to inhibit the saponification of neutral oil is of particular importance as it reduces this saponification loss one half or more. It may desirably be of such character as in effect to grain out color impurities.

Only sumcient quantity of this agent is used to inhibit saponification of neutral oil by the excess/.of the refining reagent employed, and to exert the desired de-emulsifying` action. This quantity is preferably small, seldom exceeding more than a few percent and usually being between .75% and 1.7% based von` the weight/of f the oil, thoughthese limits are not invariable and omay be departed from, being here set forthv by way of illustration. With exceptional oils containing large amounts of fatty acids, for example, above 3%, it- Amay be necessary to in crease somewhat proportionally the quantity of the de-emulsifylng and inhibiting agent.

The alcohols have been found very satisfac- 'tory as such a third agent, though various other chemical agents may be used. Monohydric or polyhydric alcohols may be used, butthe former is preferred. For example, ,'butyl, isopropyl,` 4o xpropyl,l amyl, ethyl or other monohydric alcohols give satisfactory results, those most miscible with water being preferred, for example, iso-propyl or ethyl'. Iso-propyl alcohol has been found to be particularly advantageous. The 'term Aal- 45 coho hereinafter used represents one example lof a de-emulsifying agent and includes alcohols of the monohydric or polyhydric types, or mixtures'thereof., l

` Various chemical agents other than alcohol 50 can also be used as the de-emulsifying and inhibiting agent. Various vof the esters can also be employed, for'exarnple, ethyl acetate, or the refining reagent may comprise sodium alcoholate,

potassium alcoholate, etc.

The de-emulsifying and inhibiting agent may be added bymixing with the refining reagent, or it may be added to the oil before or after addition of this refining reagent. The iirstmentioned system is preferred, the resulting rei'lning solution usually containing from 10 to 25% of the alcohol, or yother de-emulsifying and inhibiting agent, though these limits can often be departed from. For instance, with grain alcohol it is possible to use even more alcohol than water in the solution. With iso-propyl alcohol it is usually desirable that the solution of alcohol and refining reagent contain not more than thereof, though slightly more and up to can be used.

It is an object of the present invention to reduce saponiflcation of neutral oil in a batch or continuous process for reflning glyceride-type oils, and to produce other desirable results in such a process.

It is another object of the present invention to refine glyceride-type oils by use of a refining reagent and an agent inhibiting saponication of neutral oil and acting as a de-emulsifying atgent to reduce the amount of oil in the soaps oc It is a further object of the invention to add and subsequently remove this de-emulsifying and quite successful, I have found particularly good results and excellent economies in operating in a continuous manner. Any difficulty which may be experienced during batch treatment in uniformly mixing alcohol, for instance, with a large body of oil can be overcome in a continuous process by mixing small quantities of the three materials, preferably by continuously mixing suitably proportioned streams thereof. If this mixing is done in a confined space there is no loss due to evaporation, and other very desirable ends are accomplished. The mixing action can be made very complete and the resulting mixture can be moved from the mixing zone as fast as it is formed.

It is an object of the present invention to add to one portion of a continuous refining system a de-emulsifying and inhibiting agent and to re- ;nove this agent at another portion of the sys- Another object is to mix small quantities of the materials, preferably by mixing proportioned streams thereof.

Another object lof the invention is to move the resulting mixture from the mixing zone as fast as produced, preferably as a stream moving with such flow conditions that stratification or separation of the materials'is prevented, thus insuring delivery of a uniform mixture to the separating means.

A proper excess of the refining reagent is preferable in the process over and 'above the amount theoretically required to combine with the free fatty acids, the excess being that customarily used and acting on the color impurities. The removal of such color impurities is a function of time, and While with certain oils this reaction is very rapid,v some oils require a longer time of contact with this excess refining reagent. Heat may accelerate this color-removing reaction and facilitate later separation of the mixture. In the present invention flow of the mixture through an elongated zone will give this additional time, if required, and heat may be applied during this flow if desired.

Itis an object of the present invention to mix a glyceride-type oil, a refining reagent and a deemulsifying and inhibiting agent and condition the resulting mixture during flow through a passage before separating any of the materials in the mixture from the remaining materials thereof.

It is not difficult to separate the refined oil, the foots, and the de-emulsifying and inhibiting agent. Several alternatives can be used, and

- these products can be separated in various sequence. The resulting reaction products can be so treated as to first remove the de-emulsifying and inhibiting agent, for instance by vaporization, and it is an object of the present invention being applied either before and/or after theproducts enter this chamber. Heat applied ahead of this chamber may be supplied to one or more of the materials before mixing or may be supplied to the mixture. The controlling factor is that sufficient heat be used to vaporize this agent under the pressure conditions existing in this chamber, and a vacuum may be maintained'therein if desired.

Another object of the invention is to provide a method in which the foots can be at least partially dehydrated, if desired, prior to separation from the rened oil. In this connection, the invention is not necessarily limited to the use of alcohol or similar de-emulsifying and inhibiting agent, for even if a material such as alcohol is not used, I have found it desirable in many instances to evaporate water from the mixture of foots and refined oil thus removing at least a part of the Water and thus dehydrating the foots at least partially. By substantially completely dehydrating the foots it is possible to stop immediately any further tendency toward saponiiication of neutral oil, for by dehydrating the foots the ionizing power of the caustic in solution is removed, thus preventing any `further tendency to saponify neutral oil. Further, the

rend oil in the presence of@ dehydrated foots4 is much more stable and can be kept in this condition without splitting or rancidity which tend to take place in the presence of water. It is thus a feature of the present invention that water maybe removed partially or completely from the reaction products, regardless of whether or not a de-emulsifying and inhibiting agent such as alcohol is used infthe process.

It is a further object of the invention to continuously withdraw the refined oil and foots from the vaporizing zone, and to subsequently separate these materials by any suitable means such as gravitational or centrifugal separating devices, filtration, etc.

With certain types of4 separation, it is desirable to effect this separation While water is present and associated with the foots. It is an object of the present invention to provide this water either by not completely dehydrating the mousse stances, the alcohol or other de-emulsifying and` inhibiting agent apparently acting to grainout the color so that it dissolves in the water, apparently being no longer oil-soluble to any great degree. In all probability,- the alcohol acts as a peptizing agent in dissolving out, or combining with, the soluble coloring matter, preventing subsequent entanglement thereof with the oil.

However, when separating the de-emulsifying and inhibiting agent by delivering vthe reaction products to a low-pressure vaporizing zone,

there may be a tendency for the color`to be set thus making more difilcult the production of a refined oil of the desired color. 'I'his phenomena is not always present but is noticeable on certain oils, especially where the excess refining reagent has not had suflicient time to act upon the color impurities. .Any such difficulty may be overcome, and the complete process made even more effective, by preliminarily treating the oil to remove gums and mucilaginous matter.v With these removed. it is possible to readily obtain refined oil of acceptable color, and

vfying and inhibiting agent, or both, by vaporioften of a much better color than produced byv conventional processes.

It is an object `of the invention to de-gl'im a glyceride-type oil preparatory to refining and subsequent separation of water or a deemulsization.

Various other objects and advantages will be made levident to those skilled in the art from the following description illustrative of ways and means for` performing the process.

The drawing represents a pipe line diagram of a complete refining system incorporating the features mentioned above.-

Fig. l diagrammatically shows a complete system capable of prelimlnarily treating the -oil to remove gums and mucilaginous matter prepara--V tory to refining. lThe particular de-"gumming syistem diagrammatically shownin Fig. l isV very satisfactory in this regard but is not per se a part of the presentinvention, being claimed in the copending application of` Benjamin H. Thurman, Serial No. 6,446 entitled Method of treating vegetable oils and lproductI obtained thereby." Various systems, either batch or con-A ytinuous, may be used in this capacity, through co. l

.A desirable in commotion with the subsequentrening equipment.

the continuous system shown is particularly As shown in Eig. 1, the crude glyceride-type oil may be supplied to a tank' I, usually after solution gives excellent results. This prelimi` preliminary filtrationv -to remove fibrous mate-- rials or solids. The desgumming reagent in tank 2 may comprise waterralcohol, or any electrolyte such asdilute aqueoussolutions 'of acids, v alkalis, or salts used in amounts set forth in the application supra. A ten percent boric acid nary treatment, if' used,is designed to remove with the free fatty acids of the oil.

A pump 3 may continuously withdraw oil through the pre-heaters, pumps may be driven by a drive means i6, preferably of the variable-speed type, and may be4 gums and mucilaginous matter, not to react from the tank l, deliveringa stream thereof' to pipe 4. .A pump 5 may deliver a proportioned quantityy of the de-gumming reagent to the pipe l, being connected to the pump 3 by a variable speed mechanisma. These materials are intimately mixed together by any suitable mixing means, injection of one liquid into a stream of another4 having been found entirely satisfactory in this regard. The quantity of de-gumming reagent is preferably from 1 to 10 percent of the oil, yby volume, though larger quantities of the d efgumming reagent may be used.

The mixture is heated in a heater i shown as including a coil 1, positioned in a container through which a suitable heating medium is circulated, the temperature being raised to a degree facilitating centrifugal separation when the mixture is introduced into a centrifuge l.

. Here the reaction products are separated into de-gummed oil, delivered through a spout 9, and a material containing the gums, mucilaginous matter and other impurities of similar character.

The de-gummed oil enters a tank I and may be withdrawn therefrom at a rate corresponding to Vthe rate of introduction. It will be clear,- however, that if this preliminary treatment is not desired, the crude glyceride-type oil can be moved directly into the tank i0.

A tank H may contain a body of the refining reagent, and the alcohol or other 'de-emulsifying and inhibiting agent may be retained by a tank l2. If desired, any or all of these three materials may be preliminary heated in their respective tanks or may be heated in pre-heaters I Ba, lla, and I2a, before being mixed. Such preliminary heating is not necessarily used but offers one valuable way of controlling the temperature conditions in the system. If heat is applied to one or more of the three materials before mixing, particularly to the oil, it will facilitate pumping and may be used to increase the effectivenessof the later steps in the process. Even if Athe oil is pre-heated, it is not necessary in all instancesl to pre-heat the reflning solution and the alcohol or other deemulsifying and inhibiting agent. If pre-heating thereof is desired the degree of this preheatingshould preferably not be sumcient to vaporizethese materials.

By way of illustration, and for exemplary purpose onlythe process will be described with reference to continuousoperation, and withreference toy alcohol as' 'the de-emulsifying and lnhibiting agent, the refining reagent'being an aqueous alkali solution. v

In acontinuous process, it is desirable to mix' the three materials in proportioned quantities lin a conned space closed irom the atmosphere. j Preferably only small quantities of the materials are mixed at a time, and ,the mixturel is'i'p'referably maintained with such flow conditions that the ingredients of the resulting mixture remain uniformly mixed to prevent premature separation. These ends are best accomplished by. n iix- ;ing proportioned streams containing these ma-l terials.

For example, proportionlng pumpsl i3, ll and l5 `may respectively draw these materials from the tanks l0, ll` and. I2, these materials moving if desired. 'I'hese Apropi'orticnedstreamsto the" system a resulting mixture is formed in a mixing' zone which may vcomprise the forward part of a confined space de- 'ilned in part by a pipe 211|v into which the pump I3rnay directly discharge.

` Satisfactory, mixingof the three materials can l alcohol to the pipe 2liv through pipes 22 and 23, the

alcohol being supplied either upstream or downstream from v the pint of introduction of the alkali solution. On the other hand, it is often desirable to preliminarily mix the alkali solution and the alcohol to form a reilning solution which is then introduced into the oil. This may be accomplished by closing a' valve 24 in the pipe 23, and opening a valve 25 so that the pumps I4 and l5 discharge into the pipe 22, the resulting ren- -ing solution being then introduced into the pipe 2l:v toy mix with Ithe oil. In other instances, the alkali solution and the alcohol can be prelmi. narily mixed in the tank H,l the resulting refining solution being pumped through the pipe 22 into the pipe in proportioned quantity.

Various auxiliary mixing devices such as a mechanical mixer can be used if desired, but a; satisfactory'mixing can be obtained by injection of .one material intov the stream of another. This minutely disperses the alkali and the alcohol inthe oil, forming an excellent mixture and permitting the alkali to act very rapidly on the free fatty acids of the oil so Ythat the resulting foots Will be formed while the alcohol is present or immediately preceding the point of introduction'of this alcohol. The resulting mixture will include oil, foots, water, alcohol, and any excess of the alkali over and above theamounttheoretically necessary to combine with the free fatty acids,

this excess acting upon the color impurities during continued flow through the pipe 20. By pumping the materials into such a conned space, the resulting mixture will move ,from the mixing zone as fast as it is formed. It ispreferable to maintain such ilow conditions in the confined space that stratification or premature separation of any of the ingredients is prevented.

Flow along a confined space such as is defined by the pipe 20 will give this desirable action, and will condition the mixture preparatory to separation. One phase vof this conditioning involves action" of the excess lalkali on the color,

impuritiesl With some oils, this reaction is very rapid in which event the conned space need not be necessarily long to give the desired reaction time.- With other oils, a more prolonged time of contact is desirable, and a correspondingly longer confined space is desirable, thus increasing the reaction time before separation. v

It is sometimes desirable to heat this resulting mixture during iiow through such a. conilned space. In this capacity I have shown a coil 26 of a heater 21 as forming a part of the conned space, heat being supplied by any suitable means such as a'burner 30. Other types of heaters providing a conned space closed vfrom theatmosphere may be utilized, though in some instances no heat need beapplied at this point.

Flow therethrough should preferably maintain' the uniformity of the mixture in the sense that stratification or premature separation is prevented, thus insuring delivery to a separating and without deleteriously affecting the oil.

not essential. 'I'hese products are then discharged into achamber 34 deilned by a container of av separating means 35 and comprising a low-pressure zone in the event that a partial vacuum is maintained thereon.

'I'he function of this separating means is to separate the alcohol, and if desired a portionor all of the Water, from the resulting reaction products, in a vapor state. In accomplishing this end, it is sometimes desirable to apply heat to this chamber, either by circulating a hot medium through a jacket 36, or by introducing a hot medium such as steam into the chamber 34 by porized. In either instance, the requisite temperatures will depend upon the pressure in the chamber 34. All or a portion of the heat may be supplied during'pre-heating, or by heating of the resulting mixture before introduction into the chamber 34, or by heating this chamber itself.

As to permissible temperatures of the reaction products entering the chamber 34, I have found that this temperature may be as high as 160 F. or more if desired, without impairing the process This is especially true as the oil remains at such temperature for only a short time in the coil 26, the entireow to the chamber 34 being completed very rapidly, preferably within less than aiew minutes. The temperature of the reaction prod--- ucts may be as high as 180 F. or higher, though temperatures considerably higher than 160 F. are not as desirable, and even lower temperatures can often be used, especially if heat is supplied to the chamber'34. By way of/e'xample, excellent operation has been obtained by utilization of a temperature of 160 F. in the pipe 3|, with a. vacuum in the chamber 34 of approximately 26 inches of mercury and some external heat supplied thereto. If the absolute pressure in the chamber 34 is higher, correspondingly higher temperatures may be used. On the other hand, if a higher degree of vacuum is maintained in this chamber, the temperature can be correspondingly lower. I! considerable heat is supplied to the chamber 34, as by circulating heating medium through the Jacket 36 or introducing steam there- 'through, theabove temperatures can be materially lower. l

If desired, one or more bailles 31 may be mounted in the chamber 34 to move the reaction products through a. tortuous path. So also, the liquid collecting inthe lower part of this chamber may be mildly agitated to maintain the foots uniformly distributed therein.

mousse The separated vapors may be continuously withdrawn through a pipe 3b. If both water and alcohol vapors are removed, these may be iractionally condensed, or they may be condensed together and separated by means well known in the art. In the embodiment illustrated, the pipe 38 conducts the-vapors to a condenser 48, moving downward through tubes 4l thereof cooled by a medium circulated exterior thereof. This cooling may condense water vapors, the condensate mov-- ing downward in a barometric column t2 with its r,lower end submerged in. liquid in a. tank 83. The remaining vapors move through a pipe M to a condenser similarly constructed V and including a barometric column 46 'delivering the condensate, in this instance alcohol, to a tank 41. A vacuum pump 48 is conriected'to the con.- denser d5 to maintain the desired low pressure iny the chamber 34, the barometric columns' '42 and 41being of sufficient height to balancethis low pressure. f y 'I'he alcohol'l thus condensed can be moved from. the tank 41 to the tank I2 by a pump 49, being thus re-used in the process. Similarly, the water thus condensed may now, or be pumped by Va pump 5o to a tank 5i. Here caustic 'may bev supplied througha pipe 52 to` prepare the renning reagent which is then moved to the tank. Il by a pump 53.

Assuming that alcohol and some of the water has been removed in the chamber 34, the mate rial in the lower end thereof vwill comprise a mixture of reiined oil and roots which have beenat least partially dehydrated. The 4color impurilties, also dehydrated at least partially, wiilbe associated with these foots. This oil-footsmixture is preferably removed continuously from the chamber 34 by any suitable withdrawal means acting in such a manner as not to impair the vacuum in this chamber. can be used, as diagramrnatically indicated by ,the numeral 68. If desired, this withdrawal means may comprise a barometric column through which the oil-roots mixture moves downward, and being of sumcient height to balance the low pressure in the chamber 34.

This oil-roots mixture may be moved 4directly a means indicated by the numeral '68- for increasing, decreasing or maintaining the temperature' theof. By way of example, the mixture may how through a coil 18 positioned in a container 1l through which a heat-control medium' is circulated, the mixture being discharged continuously into a pipe 12. Heat applied at this point will facilitate separation in various separating systems, though in many instances the oil-foots mixture will already be at a temperature satisfactory for separation. On the other hand, better separating action witl other separating systems may be' obtained ii the' oil-foots mixture is cooled at this point.

In some instances a better separation can be obtained iffthe foots are. not completely dehydrated, though in other instancesv dehydration is advantageous. Any desired amount of water can be left in the foots by proper control of temperature and pressure.I Alternatively, if the roots have been dehydrated in the chamber 34 lt is possibleto re-hydrate th/emto any desired degree. -For instance, water may be supplied either as a liquid or vapor to the oil-roots mixture after being withdrawn from the chamber 34. This water may be added either charge sides of the pump meansi; As illus- Various types of pumps on the intake or disthe oil-roots mixture. One very advantageous` way is to effect this separation by filtration, regardless of whether or not the oil was first de- 'gummect However, such de-gumming will de- 'crease the amount of foots present in the oil-4 foots mixture and can be advantageously used when separating by iiltration.

n a is desired te interi thefoir-footslmixwre this can bedone by closing a valve 13 and open-` ing "a valve 14 so that the mixture will iiowto a filter 15, By way of example, this iilter is shown vas ofthe continuous rotary type including a troughi-like pan I6 into which the mixture discharges. The usual rotatable drum 11 dips into this pan and provides a. peripheral -iilter 18. A- vacuum is maintained in a chamber 19 inside this drum by use` of a vacuum pump 8B communieating' therewith through a pipe 8i at one end v4of the drum'. Such a vacuum forcibly draws refined oil through the iilter 18, the foots being deposited thereon. This oil may be continuously withdrawn from the chamber 1S by a vacuum pump 82 through a .pipe 83 communicating with the other end oi this chamber. The foots are, scraped from the rlter ,18 by a scraper 8d and` move through a passage 85 to a conveyor housing 86. They are advanced therealong by a screw 81 rotating therein, being extruded through an. extrusion means 88. the event that the sys-s tem is operated with e interior of the'A lter housing -at sub-atmosphericpressure, this screw means will continuously withdraw the foots and increase vthe pressure thereon sufciently to ex-u trude these through the y means 88.

If filtration is used, best results are obtained if the foots have been at least partially deny--l drated. Substantially anhydrous foots can be leasily separated by this type of lter, but if de. sired some` moisture may be added thereto through-the pipe 98.

It is often desirable to centrifugally separate to a separating means, or it can be moved through f the mixture 0f refined 011 and fOOtS- BY 01081118 the valve 14' and opening valves 13 and 9| this mixture may flow to a centrifuge 82. The usual high-speed centrifuge can be used, the refined oil andl foots respectvelydischarging through spouts 93 and 84. However, superior separation, lower refining losses, and continuous .operation over long periodsiof time can be effected by utilizing a heated-centrifuge fsuch as is disclosed in the application filed August 1, 1935, Serial No. 34,258, now Patent No. 42,100,277, granted November 23, 1937. .For instance, agheating medium such as steam may be suppliedV through a pipe 95 tothe exterior of the rotating bowl of the centrifuge.

Ifcentrifugal separation is utilized, it is not desirable that theioots be completely anhydrous, otherwoise continuous discharge thereof from .the centrifuge cannot be satisfactorily eiiected.

' Such continuous operation can be insured by removing only a portion, or none, of the water Sil It is also possible to lseparate the mixture of refined oil and foots by other means. For inclosed, and the alcohol or other ie-emulsifyingl and inhibiting agent removed by vaporization, followed by separation of the ol and foots.

If continuous operation is used, the invention includes among its novel concepts the provision of a system in which the resulting mixture may be moved along a conned space, the de-emulsifying and inhibiting agent being vaporized and removed from one portion of this space.- For instance, the pipe 20, the coil 26, and the chamber 34 may comprise this conned space. In this way, the de-emulsifying and inhibiting agent can be added to one portion of such a' space and removed from another portion thereof. This permits recovery and' re-use of such an agent with very small loss.

However, it will be clear that the invention is not in all instances limited to the use of a deemulsifying and inhibiting agent. Even if not used, desirable results can often be -obtained from the process in producing partially or completely dehydrated foots as a part of a continuous refining system. This dehydrationof the foots often facilitates separation of the oilfoots mixture and stops saponiiication of neutral oil, also producing other desirable results.

I claim as'my invention: p

1.A process of refining a glyceride-type oil, which process includes the steps of: mixing proportioned quantities of said glyceride-type oil, an alkali rening reagent capable of reacting with the free fatty acids in said oil to form foots and added in amount greater than theoretically required for reaction with said free fatty acids, and a de-emulsifying Vand inhibiting agentl selected from the group consisting of the lower aliphaticY alcoholsand their esters added in such amount as to minimize the saponication and entrainment of neutral oil; separating said de-emulsifying and inhibiting agent by vaporizing the same from the resulting mixture, leaving a mixture of rened oil and foots; and separating the foots and the rened oil. l

2. A vprocess of reiining a glyceride-type oil, which process includes the steps of: removing gums and`mucilaginous matter from said oil; mixing proportioned quantities of Asaid glyceridetype oil, an alkali rening reagent capable of reacting with the free fatty acids in said oil to form foots and added in amount greater than theoretically required for reaction with said free fatty acids, and a de-emulsifying and inhibiting agent comprising a lower aliphatic alcohol added in such amount as to minimize the saponification and entrainment ofneutral oil; separating Ysaid de-emulsifying and ,inhibiting agent byl vaporizing the same iromthe resulting mixture, leaving a mixture of refined oil andfoots;l and separating the footsand the`efined oil.

q 3. A .processof refining glyceridetype oils' whichincludesthe steps of: continuously mixing in aconiinedspace proportioned streams of vsaid glyceride-type -oi1,f an alkali rening reagent Awhich includes:

capable of reacting with the impurities in said oil to form foots, and a de-emulsifying and inhibiting agent comprising a lower aliphatic alcohol used in such amount as to minimize the saponication and entrainment of neutral oil; continuously separating said agent from the resulting mixture by vaporizing said agent from said mixture to leave a mixture of refined oil and foots; and separating said refined oil from said foots.

4. A process of reiining a glyceride-type oil removing gums and mucilaginous matter from said oil; continuously introducing into a conned space a stream of the oil thus preliminarily treated; continuously introducing into said confined space and mixing with said preliminarily 'treated oil therein proportioned quantities of an alkali rening reagent.

capable of reacting with the free fatty acids of said oil to form foots, and a de-emulsifying and inhibiting agent comprising a loweraliphatic alcohol used in such amount as to minimize saponication and entrainment of neutral oil; continuously separating said agent from the resulting mixture by vaporizing'said agent from said mixture to leave a mixture of rened oil and foots; and separating said rened oil from said foots.

5. A process of rening glyceride-type oils which includes the steps of continuously introducing into a confined space and mixing therein proportioned quantities of said glyceride-'type oil. an alkali refining reagent capable of reacting with the impurities in said oil to form foots, and a vaporizable agent selected from the group consi'sting of the lower aliphatic alcohols and their esters, to form a mixture which is moved along said conned space; heating said mixture during flow through said confined space; continuously vaporizing said vaporizable agent and removing the resulting vapor from one portion of said conned space; 'continuously removing a mixture of rened oil and foots froin another portion of said confined space; and separating said refined. oil and said foots thus continuously removed.

6. A process of refining glyceridetype oils which includes the steps of: introducing into a confined space and mixing therein proportioned quantities of said glyceride-type oil, airalkali rening reagent capable of reacting with the impurities in said oil to -form foots, and a vaporizable agent selected from the group consisting of the lower aliphatic alcohol:-f, ;md their esters, to' form a mixture which is moved continuously along said confined space; continuously introducing the resulting products into a low-pressure zone; removing said agent in vapor state from said low-pressure zone; continuously removing the resulting vapor from lsaid low-pressure zone; continuously removing a mixture of rened oil 'and foots from said zone without impairing 'the low pressure therein; andseparating said refined oil and said foots.

7; A process of reiining glyceride-type oiis which includes the steps of; continuously introducing and mixing in a relatively confined space closedfrom the atmosphere proportioned streams of said glyceride-'type oil, an alkali rening'reagent capable of reacting with the impurities in said oil to produce foots, and a vapori'zable imI aiaoss a tinuously introducing the heated mixture into a larger zone closed from the atmosphere and with-` out exposing said heated mixture to the atmosphere before introduction thereinto; continuously removingvapors of said agent from said larger'zone to leave a mixture of rened oil and foots; continuously removing said mixture of refined oil and foots from said larger zone; and separating said refined oiland said foots.

8. A ,process of refining glyceride-type y oils which. includes the steps of: continuously mixing inv a confined space proportioned streams of. said glyceride-type oil, analkali refining reagent capable of reacting with the impurities in said oil to form foots, and a lower aliphatic alcohol, the quantity of said refining reagent being in ex-` cess of that 'required to react with the free fatty acids, and the quantity of said alcohol being sufficient to minimize saponification and entrainrnent of neutral oil; continuously moving the resulting mixture through said confined space, thus permitting the excess refining reagent to act" upon the color impurities of said oil while said alcohol is present; continuously separating the alcohol from the resulting reaction products to yleave a mixture of refined oil and foots; returning at least a portion of the thus separated alcohol to said coni-ined space to form at least a portion of the proportioned stream of alcohol delivered thereto; and separating said refined oil and said foots.

9. A process 'of refining glyceride-type oils which includes the steps of: mixing in a space closed from the atmosphere proportioned quantities of glyceride-type oil, an aqueous alkali refining reagent capable of reacting with the impurities in said oil to form foots; and a vaporizable de-emulsifying and inhibiting agent comprising a lower aliphatic alcohol, thus forming reaction products including oil, water, foots, and said agent; vaporizing said agent and, at least a portion of said water from said reaction products during ow through a confined space to at least partially dehydrate said foots; removing from said confined space said vapors ofsaid agent and water 'to leave a mixture of refined oil and foots which have been at least partialiy dehydrated; and separating the foots from said rened oil.

10. A process of refining glyceride-type oils which includes the lsteps of: forming a-mixture in a space substantially .closed from the atmosphere of proportioned quantities of said glyceride-type oil, an alkali refining reagent capable of reacting therewith to form foots, and a vaporizable agent selected from the group consisting of lower aliphatic alcohols and their esters; introducing a stream of the resulting reaction products into a low-pressure zone; apply-- ing heat to said low-pressure zone to vaporize said agent; withdrawing the resulting vapors from said low-pressure zone; and separating said foots from the refined oil. Y

11. A process of refining glyceride-type oils which includes the steps of: bringing together in mixing relationship-in a confined space proportioned streams of a glyceride-type oil, an alkali refining reagent capable of reacting with the impurities of said oil to forms foots, and a vaporizable de-emulsifying and inhibiting agent comprising a lower aliphatic alcohol; continuously vaporizing said de-emulsifying and inhibiting agent by heating a stream of the resulting mixture and introducing same into a separating zone; continuously removing the resulting vapors from :and separatingzone to leave a mixture of rened oil and foots and filtering said foots from said revtinuously removing the resulting vapors from said separating zone to leave a mixture of refined oil and foots; and. subjectinga stream of said mixture of refined oil and foots to a centrifugalV separating action to separate said foots from said refined oil.

13. A process of refining glyceride-type oils containing fatty acids, which process includes the steps of: neutralizing said fatty acids in the presence of notmore than a few per cent of a lower aliphatic alcohol; then .vaporizing the alcohol while maintaining the foots uniformly dispersed 25 in the oil; and then separating the foots from the oil.

14. A process as defined in claim -13 in which said alcohol is separated by vaporization while the mixture containing oil, foots and alcohol is sa then'vaporizing the alcohol while maintaining the foots uniformly dispersed in the oil; and then separating the foots from the oil.

1 6. A process of refining a glyceride-type oil, di, ywhich process includes the steps of: mixing proportioned quantities of said glyceride type oil, an alkali refining reagent capable of reacting with the free fatty acids in said oil to form foots and added in amount greater than theoretically rew quired for reaction with said free' fatty acids, and a de-emulsifying and inhibiting agent comprising a lower aliphatic alcohol which is more volatile than the oil and which is added in such amount as to minimize the saponification and entrain- 50 lment of neutral oil; vaporizing said de-eniulsifying and inhibiting agent from the resulting mixture, leaving a mixture of refined oil and foots; and separating the foots and the refined oil.

17. A process of refining a glyceride-type oil, u which process includes the steps of: removing gums and mucilaginous matter from said oil; mixing proportioned quantities of said glyceridetype oil, an alkali refining reagentcapable of reacting with the free fatty acids in said oil to o0 form foots and added in amount greater than theoretically required for reaction with said free fatty acids, and a de-emulsifying and inhibiting agent comprising a lower aliphatic alcohol which is more volatile than the oil and which is added g5 in such amount as to minimize the saponication and entrainment of neutral oil; vaporizing said de-emulsifying and inhibiting agent from the resulting mixture, leaving a mixture of refined oil and foots; and separating the foots and the re- 10' fined oil. A

18. A process of rening glyceride-type oils which includes; continuously introducing into a confined-space and mixing therein proportioned quantities of a glyceride-type oil, an alkali ren- 'I5 ing reagent capable of reactingwith the free fatty acids in said oil to form foots, and a deemulsifying and inhibiting agent comprising a lower aliphatic alcohol which is more volatile than the oil and which is used in such amount as to minimize the' saponication and entrainment of neutral oil; vaporizing said agent from said mixture in said conned space; continuously removing the vapor of said agent from said confined space to leave a mixture of rened oil and foots; and separating said foots from said rened oil.

19. A process of kreining a glyceride-type oil which process includes: m'ixing proportioned quantities of said glyceride-type oil, an alkali rening reagent capable ofI reacting with the free fatty acids of said oil to form foots and added in quantity in excess of that theoretically necessary to react with said free fatty acids, and a deemulsifying and inhibiting agent, comprising a lower aliphatic alcohol which is more volatile than the oil and which is added in suiiicient quantity to minimize the saponication and entrainment of neutral oil; continuously moving the resulting mixture along a passage closed from the atmosphere; vaporizing said de-emulsifying and inhibiting' agent from the resulting mixture While in said passage and removing the resulting vapors from said passage to leave a mixture of refined oil and foots; and continuously separating said foots from the refined oil.

20. A process of refining glyceride-type oils which includes the steps of: continuously bringing together in mixed relationship in a conflned space proportioned streams of a glyceride-type oil, an alkali refining reagent capable 0fA reacting with the impurities of said oil to form foots, and a vaporizable de-emulsifying and inhibiting agent comprising a lower aliphatic alcohol to form a stream of products moving along said conned space; continuously vaporizing said agent from said stream during movement in said confined space to leave a mixture of reiined'oil and foots substantially free of said agent; contin-l uously removing the vapors of said agent from said confined space; and subjecting a stream of said mixture of rened oil and foots to centrifugal force while applying heat to the zone in which the centrifugal force is applied, thereby continuously separating the foots from the re- 

